0025 Risco, Sima-Cueva del (Risco, Sistema del)
Ozana 30T 453301 4796054 Altitude 188m Length 10167m Depth 25m

Updated 19th February 1999; 28th July 2000; 26th October 2001; 2nd March, 6th October 2002; 6th November 2003; 8th October 2005; 26th September, 28th October, 17th November 2007 ; 25th September, 19th November, 19th December 2008; 8th May, 23rd October, 18th November 2009; 28th January, 30th September 2010; 6th January, 10th May, 1st October 2011

The usual entrance, Torca del Sedo is situated behind a group of houses at Sedo. [The tap at the water trough above the entrance has been GPS'd to 30T 0453308 4796059 to give an altitude of 193m. This gives the position and altitude of the entrance above. The length above is the combined Risco - Tiva - Oñite in the re-survey, not yet complete.]
A short clamber down leads to the 8m pitch head. The descent can be damp and the base is strewn with rubbish. Two ways are possible at the bottom: downstream leads into Cueva de Tiva (026) - apparently blocked with white goods and domestic rubbish during the summer, 2010 - while a 2m climb in the opposite direction leads into the entrance series of Risco.

After 100m of large passage the stream is met and wading in 1m deep pools is needed. To the left are two high level passages both of which choke after about 100m. In April 2011, a high level passage was entered in this area but choked in both directions over the stream (survey batch 0025-11-01 and DistoX drawing). Straight ahead the streamway continues high and wide to a junction with a passage on the right. This leads to several dismal chambers and no way on is possible. The main streamway continues through deep pools and mud banks until the Tonto Series is met on the right. This uninviting, low passage splits after 200m and then chokes.

The Dambuster Series is reached by climbing across the top of 30m avens on the south side of the passage just before reaching the Tonto Series. Five metre diameter, well decorated, parallel passages with deep holes end at a sandstone breakdown. This was resurveyed, extended and photographed during summer, 2008.

The main passage runs for another 100m before reaching the most important junction in the cave. At this point the right hand, narrow and very wet passage can be followed up to the superb Pinto Gallery. This vadose passage contains a large stream and can be followed for almost 2km until it splits into the various feeder inlets which have their origins in the Jivero/Tali/Anderal complex of caves. Although there is much evidence of surface debris, no surface connection has been made. Archaeological finds made in this area are described below.

Back at the main junction it is possible to climb up straight ahead into a large boulder chamber where 2 routes are possible. The fine Arco Gallery goes off at high level and is typically 3 - 5m wide and 15m high. This runs for 400m, around two holes, until it breaks out into the roof of the Risco River Gallery and progress is halted. (In 1992, on the way back, two passages on the left were looked at. Chambers at the end were reached by smashing through stal). In fact the Arco Gallery is the old, abandoned route and the present stream has cut down to a lower level. This can be joined from the boulder slope at the start of the Arco Gallery and is easy going except for the occasional climb over boulder piles.

The Risco River Gallery continues for approximately 1km until it emerges into the impressive Sala Carballo which is a large boulder filled chamber. The main inlet tumbles down from high up on one wall - this is the 19m pitch in from Cueva Oñite (site 027). This has been bypassed with a route through from Oñite discovered in 2005.

On the opposite side of the Sala Carballo a large dry passage (Gran Risco) heads off above the main river and probably originally connected with the Arco Gallery. After 300m it becomes choked with calcite deposits.

In 1994, the deep hole down to the river at the end of the Arco Gallery was traversed over. A bolt route leads up to the left after a 4m climb over boulders. This reaches a dangerous climb up through boulders and a slot up into a big chamber. Most routes are well decorated with calcite. The upper gallery goes back across the chamber. A side passage up a 15m climb leads to Disney World with amazing formations including a triangular mono crystal stalagmite about 1m high. (A photocopy of a section from Cave Minerals of the World is in the Risco file). The route continues as the high level Arco 2. Solid roof is seen with no indication of any inlets from Muela / Mullir. Some 300m along it is possible to abseil down into the main Arco Gallery (photos) and this is the safest way up to the extensions. Arco 2 ends at a traverse with no ledges where bolting is required.

Archaeological remains have been discovered. The S.E.S.S. found remains of a large deer, possibly Cervus megaceros. In 1975, in the same area (the end of the Pinto Gallery), L. Mills discovered a palaeolithic bone spearhead also described as a mono-bevelled bone assegai, 8.5cm in length and with a circular cross-section, possibly Magdalenian.  More recently, the possibility of more remains and small engravings has been published. Photographs of engravings on the walls can be seen here. (See also Ruiz Cobo Jesús and Smith Peter et al, 2001). Smith Peter, 2006 concludes that there are 2 figures of ibex and that the assemblage can be dated to the early-middle Magdelenian, although Ruiz Cobo Jesús et al, 2008, p96 suggests that the engraving is similar to that in Cueva del Otero. A survey fragment (from Ruiz Cobo Jesús et al, 2008) appears here.

Ortiz in Algunos crustaceous y miriapodas cavernicolas de la Region de Matienzo, Santander (Ortiz E, 1968) describes 18 individuals of Gammarus berilloni Catta.

A dye test in 1964 showed water from Sima-Cueva del Risco resurging after five hours from La Lisa below Cueva de Gonzales (014), Cueva de Transformador (032) and in Cueva de Tiva (026).

The cave is currently being resurveyed, coordinated by Pete Smith. In November, 2009, 250m was surveyed with some "new" passage where oxbows were surveyed.
In summer 2010, attempts were made to reach the middle level where it is "missing" half way along the cave. One climb of 8m led to an area of shale and loose rock with no place to fix bolts. The second climb was found 50m to the north with an easy route up to a loose area. Rope was fixed to two good bolts at a Y-hang. Probably 6 more bolts are required but the problem will be finding rock to fix into. "Big passage" can be seen above. Another attempt was made at Easter 2011.
In the summer 2011, a climb into a possible Arco continuation failed due to poor rock. However, a climb near to Risco entrance succeeded in entering 102m of good size passage above the stream.
References: Fernández Gutiérrez Juan Carlos, 1965; Fernández Gutiérrez et al, 1966 (survey and photo); anon., 1974b (logbook); anon., 1974a (survey); Cox G, 1973; Fernández Gutiérrez J C, 1975; anon., 1975b (logbook); Kendal Caving Club and Manchester University Speleological Society, 1975 (survey and photo); anon., 1977b (logbook); anon., 1978 (logbook); Manchester University Speleological Society, 1982 (survey and photo); Mills L D J, 1981; Mills L D J and Waltham A C, 1981 (survey); Mills L D J and Waltham A C, 1981 (survey and photo); Smith P, 1981a; Corrin J S and Smith P, 1981; anon., 1981 (logbook); anon., 1982 (logbook); Corrin J, 1983c (photo); anon., 1986 (logbook); material in file; Ortiz E, 1968; anon., 1992b (logbook); Cawthorne B, 1992; Corrin J, 1992b (survey); anon., 1993b (logbook); Muñoz E and Bermejo A, 1987; anon., 1994b (logbook); Corrin J, 1994b (survey); Fernández Ortega F, Valls Uriol and Maria del Carmen, 1998; García José León, 1997 (survey and photo); Corrin Juan, 1997c; anon., 1999c (logbook); Corrin Juan, 2001a; Ruiz Cobo Jesús and Smith Peter et al, 2001 (includes drawing); anon., 2002b (summer logbook); Corrin Juan, 2003b; Ruiz Cobo Jesús and Smith Peter, 2003; anon., 2005b (Easter & summer logbook); Corrin Juan, 2006a; anon., 2006d (summer logbook); Smith, Peter 2006; anon., 2007d (summer logbook); Corrin Juan and Smith Peter, 2007; Corrin Juan, 2007a; anon., 2008e (summer logbook); Ruiz Cobo Jesús et al, 2008 (survey) ;anon., 2009d (autumn logbook); anon., 2010c (summer logbook); León García José, 2010 (survey and photos); Corrin Juan, 2011; anon., 2011b (Easter logbook);
Entrance picture : yes
Underground picture(s):
photos from Easter 2011 (Phil Papard)
photos from summer 2010 (Paul Dold)
photos from summer 2009 (Steve Martin)
photos from summer 2008 in the Dambuster Series
photos from summer 2007 in the main galleries
near the end of the Pinto Gallery

Scanned slides from 1977, 1978 by Frank Addis

water- fall

tusk

Detailed Survey : from 1965: low res  high res  Oñite survey updated 2005  
from rescue site (Risco, Tiva and Oñite)  low res  high res
survey fragment of the archaeology finds (Ruiz Cobo Jesús et al, 2008)
survey fragment: batch 0025-11-01 high level extension just upstream of entrance, DistoX plan file
Line Survey :
On area survey : 1975 Ozana area map. Not a lot of detail. low res  high res
Survex file : yes, with Oñite (latest after summer 2010) and batch 11-01 (Easter 2011)
Passage direction rose diagram (Patrick Warren): yes, with Oñite and Tiva